Lighting systems based on LEDs are used on an increasing scale. LEDs have a high efficiency and a long life time. In many lighting systems, LEDs also offer a higher optical efficiency than other light sources. As a consequence, LEDs offer an interesting alternative for the well known light sources such as fluorescent lamps, high intensity discharge lamps or incandescent lamps.
LED light sources are often comprised in a lighting system, wherein the operation of the LED light sources is controlled by control commands. Such control commands include commands for activating the LED light source and commands for stopping the operation of the LED light source, i.e. commands to start generating a LED current and commands to stop generating a LED current, respectively. In the latter case, operation is not stopped by interrupting the connection of the LED light source to the mains supply but by stopping for instance the operation of a converter circuit comprised in the LED light source. In this latter case, the LED light source is said to be in standby mode. In this standby mode, since the mains supply is still connected to the LED light source, the LED light source is still capable to receive further commands and process those commands. At the same time, however, the mains supply may cause a leakage current through parasitic capacitances and (part of) the LED load comprised in the LED light source. This leakage current can cause the LED string to generate a small amount of light resulting in a glow effect that is often undesirable.